Even at this late date, there is a great need in farming to provide a fastener or staple for use with either metal or wood posts to accommodate barbed wire between a summer taut position and a winter loose position. The staple must be able to accommodate sliding movement of the barbed wire between the two positions while at the same time provide the required support in case animals or the like bump into the wire. Many staples have been suggested, such as those disclosed in U.S. Pat. No. 1,540,755, issued to Brady, June 9, 1925 and U.S. Pat. No. 631,138, issued to Timmons, Aug. 15, 1899. Both of these patents illustrate staples useful with barbed wire, but neither of the patents shows a staple of the type hereinafter described. The staple of the present invention provides means for positioning an enlarged eye a predetermined distance from the associated post and also provides means for easy passage of the barbed wire therethrough in combination with a staple of a design such that it is easy to handle in the field, inexpensive to make and is essentially one piece construction.